Our studies concern the organization of the visual pathways in selected mammalian species with distinct phylogenetic histories. Specific studies concern the morphology and physiology of retinal ganglion cells, and their topography (distribution over the retina), leading to a functional classification of these cells. Further studies concern the connections made in the various visual centres of the brain by different classes of ganglion cell. Much has been learnt, and is still to be learnt, concerning the organization of brain visual centres in terms of how they handle the input they receive from different classes of ganglion cells. By studying a range of species (cat, rabbit, marsupials, primates), we have gained some understanding of which features of the visual pathway are common to mammals, presumably reflecting their common phylogenetic ancestry, and which are specific to particular species, presumably reflecting their particular development and adaptation.